Shape memory self-ligating orthodontic brackets

ABSTRACT

Self-ligating orthodontic brackets, each of which is formed of materials exhibiting shape memory and includes a base from which extend at least one tie wing. The tie wing includes a pair or tie wing posts which are normally spaced to retain an archwire within the guide slot. At least one of each pair of opposing tie wings is flexible and/or yieldable relative to the other to permit insertion and/or removal of the archwire relative to the guide slot. Portions of the brackets may be coated to reduce friction between the archwire slot and the archwire and to promote aesthetics and overall bracket appearance.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part application of U.S. patent application Ser. No. 10/882,165 to Nicholson, filed Jul. 2, 2004, entitled “Shape Memory Self-Ligating Orthodontic Brackets,” the subject matter of which is herein incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention is generally directed to orthodontic brackets that are used to align teeth and that include at least one tie wing having a pair of tie wing posts to selectively and guidingly receive an archwire within an archwire guide slot defined between the tie wing posts. More specifically, the invention is directed to self-ligating orthodontic brackets at least partially formed from shape memory metallic or non-metallic materials.

2. Brief Description of Related Art

Generally, there are two basic styles of orthodontic brackets. A first style is known as a single wing wherein a single tie wing extends upwardly from a bracket base. The tie wing includes a pair of opposing tie wing posts that are spaced to define an archwire guide slot therebetween. An example of a self-ligating single wing style bracket is disclosed in U.S. Pat. No. 6,663,385 to Tepper.

Twin brackets are the second style of brackets and have been developed to increase ease of bracket use and placement. Twin brackets include a pair of opposing tie wings which are spaced from one another with each tie wing defining an archwire guide slot therebetween. An example of such a twin bracket is described in U.S. Pat. No. 5,232,361 to Sachdeva et al., wherein the bracket is formed of titanium so as to be very hard and rigid. An example teaching away from a spaced pair of tie wings is disclosed in U.S. Pat. No. 5,356,289 to Watanabe, wherein the brackets are formed of shape memory alloys or resins.

A variation of the twin bracket style has been developed to make the twin brackets self-ligating in order to avoid the necessity to tie-off the archwire used with the brackets. Such self-ligating twin brackets use supplemental hooks or latches which are mounted adjacent to each pair of tie wings for securely engaging or clamping an archwire. Unfortunately, the additional structures not only increase bracket costs and size, but also decrease bracket aesthetics and provide additional structures for trapping food and bacteria. Thus, the additional structures associated with conventional self-ligating brackets cause problems for both patients and orthodontists during treatments. An example of such a bracket is described in U.S. Pat. No. 6,554,612 to Georgakis et al.

Orthodontists are faced with many treatment difficulties as they bond orthodontic brackets to a patient's teeth and move them from crooked and irregular malocclusion positions to their ideal positions. The ideal alignment of teeth demands that they must be straight and aesthetically pleasing, but the teeth must also fit together correctly into normal occlusion and look and function in a superior clinical manner. There are a number of major challenges that orthodontists must overcome to produce this superior clinical result.

There is often limited access to areas of the teeth where brackets must be placed to achieve normal orthodontic movement and produce superior treatment results. Useful areas are small with access thereto very restricted, in which case, large brackets are not used successfully; whereas, smaller and compact size brackets can be placed in small areas and have enjoyed exceptional popularity among orthodontists.

Ideal bracket placement on a patient's teeth is also necessary to produce ideal tooth alignment and achieve exceptional orthodontic results. To accomplish this necessary goal of ideal placement, brackets must often fit into small spaces between crooked and rotated teeth. For example, a recessed point, vertical scribe line, or horizontal groove located in the approximate center of a bracket permits an orthodontist to use a measuring device, such as a Boone Gauge, to precisely position the bracket on a tooth in an exact desired position. In addition, color-coded recessed markings on the brackets assist the orthodontist visually to align and orient the bracket correctly on the teeth.

Complete archwire engagement of the brackets on the teeth during various stages of orthodontic treatment is important, but may not be possible. Many times, due to crooked alignment and closeness of the teeth, only some of the posts of the tie wings of the brackets can be engaged at the same time. This can result in an uncontrolled and unsatisfactory tooth movement. A smaller bracket size permits more tie wing posts to be engaged and subsequently improves tooth movement.

The tooth movement process that is required to straighten teeth is very dynamic and constantly changing. The orthodontist must have brackets that will accommodate the dynamics of tooth movement and not require replacement with new ones when a certain movement is required due to the difficulty of a patient's case. Further, attachments such as Kobayashi hooks, removeable hook pins, uprighting springs, metal ligatures, directional force elastics, elastomeric ties, or elastomeric power chains are often used during various stages of orthodontic treatment. An orthodontist places these attachments to tie wing posts or in vertical slots to satisfactorily accomplish different aspects of a treatment.

Friction occurs as a normal part of tooth movement as a bracket and tooth slide along an archwire. This process is known as the sliding mechanics of orthodontics. More points of contact between the archwire and a bracket slot during this process causes greater friction, which results in slower tooth movement and makes the treatment take longer. Larger brackets have increased friction resistance to tooth movement, and thus treatment involving larger brackets is lengthy and more complicated to complete.

The aesthetic demands of an orthodontic patient are many and must be addressed to make a treatment acceptable to the patient. Smaller and less noticeable brackets are more aesthetic than larger brackets, and the bracket aesthetics can be further improved. The single wing and double wing brackets allow the orthodontists to attach colorful elastics, elastomeric ties, and elastomeric power chains to the brackets that are pleasing to the patient.

A further major challenge to orthodontic treatment is the cleanliness of the brackets and areas where they are bonded or banded to the teeth. It is difficult for patients to clean areas adjacent to brackets and tooth surfaces. Bracket elements function as plaque traps that increase the chance of permanent stains, tooth decay, and gum disease. The use of larger brackets makes it much more difficult for patients to keep their braces clean. The smaller bracket designs are much easier for patients to clean and greatly reduces the amount of trapped food. Thus, smaller brackets are less likely to cause stains, tooth decay, or gum disease.

During the course of orthodontic treatment, archwires are placed and removed from the archwire slot as a normal part of treatment. Since most orthodontic brackets are made of stainless steel, both the bracket and archwire slots are rigid and inflexible. Once an archwire is placed in an archwire slot, the archwire must be tied or ligated in place to prevent the archwire from coming out of the bracket and injuring the patient. The process of tying and untying every bracket to secure the archwire is a tedious and laborious procedure that must be repeated each time a new archwire is placed or removed. This process is time consuming and uncomfortable for the patient and inefficient for the orthodontist. Self-ligating brackets have the advantage of using various mechanisms to secure archwires in the archwire slots without the need for metal or elastic ligatures. However, the current self-ligating brackets are bulky and cumbersome to use in the small confines of the oral cavity.

In the 1980's, nickel-titanium was introduced to orthodontics in the form of archwires named Nitinol™. The flexibility, shape-memory effect, and super-elasticity of Nitinol™ archwires offered a new wire that could be deflected to engage misaligned teeth and would return to its original form, thereby straightening the teeth. The flexibility, shape memory effect, and superelastic nickel-titanium material has not, however, been used to construct a flexible bracket that looks and is shaped like the traditional stainless steel brackets.

SUMMARY OF THE INVENTION

This invention is directed to orthodontic brackets, wherein each bracket comprising a unitary body structure including a base from which extends at least one tie wing having a pair of tie wing posts. Each tie wing post includes a head portion and a body portion, and each pair of opposing tie wing posts defines an archwire guide slot therebetween that is usually of a dimension between approximately 0.018″ to 0.022″ to slidingly receive an archwire. The head portion of each tie wing post has an inner flange which is spaced closely adjacent to, or in contact with, an inner flange of an opposing tie wing post in a normal position so as to prevent unplanned removal of an archwire seated within the archwire guide slot between the tie wing posts. The head portion of each tie wing post further includes an outwardly extending flange which may be used for securing archwires with ligating wires or for adding other attachments that may be required during a patient's treatment.

In the present invention, an orthodontic bracket includes at least one tie wing post that is formed of a shape memory material, such as a metallic alloy, including nickel-titanium, or a non-metallic material, including resin and polymer type materials, so that at least one tie wing of the bracket exhibits some degree of flexibility and shape memory. Thus, at least one of the opposing tie wing posts may be flexed such that the head portions of the opposing tie wing posts may separate to a distance to permit the insertion and/or removal of an archwire relative to the archwire guide slot defined therebetween. The nickel-titanium alloy or other material exhibiting a shape memory causes the tie wing post or posts to return to a pre-determined position after an archwire is either inserted into or removed from the slot between the tie wing posts. In preferred embodiments, at least one of each of the opposing tie wing posts of at least one tie wing is formed of a shape memory material so that the at least one tie wing post may be flexed to permit insertion and/or removal of an archwire from the guide slot.

In a twin bracket embodiment of the present invention, a pair of opposing tie wings are spaced from one another and extend from the front surface of a bracket base such that the archwire slots formed between the tie wing posts of each tie wing are generally axially aligned relative to one another. In other preferred embodiments of the invention, either a recessed point, scribe line, or horizontal groove is provided at or along the approximate center of each bracket base for purposes of precision alignment of the bracket with respect to a tooth using an instrument, such as Boone gauge.

To reduce friction between an archwire and the orthodontic brackets of the present invention, at least a portion of the brackets, may be coated with a metallic material, a non-metallic material, a polytetrafluoroethylene (PTFE) material, such as Teflon™, a thermosetting polymer, or other polymeric coatings with or without a coupling agent to form a smooth surface between the bracket and the archwire. To promote adherence of the coating, the brackets may be physically, chemically, or otherwise treated, such as by a blasting process, chemical etching, micro-etching, or the like. Archwires associated with the brackets of the present invention may also be similarly coated.

As opposed to plastic or polymer coatings, the brackets of the present invention may be plated or electroplated with a metallic material, such as nickel, gold, copper, silver or the like, in order to reduce friction of the bracket surface to promote sliding of an archwire relative to the brackets during patient treatment and/or to enhance aesthetics.

It is a primary object of the present invention to provide orthodontic brackets which are self-ligating and which are entirely or partially formed of a shape memory metallic material, including alloys, such as nickel-titanium, or a shape memory non-metallic materials, including resins and polymer type materials, so as to allow flexibility of at least one tie wing post when a bracket base is securely bonded to a tooth or welded to a band that is cemented to a tooth. Further, the shape memory material allows the components of the bracket to exhibit super elasticity so that at least one of the tie wing posts may be flexed to permit insertion and removal of an archwire therebetween and thereafter immediately recover to a predetermined configuration and position to retain the archwire in the slot defined between each pair of opposing tie wing posts.

It is another object of the invention to provide self-ligating orthodontic brackets that are formed at least partially of a shape memory material and that includes a pair of tie wings, wherein at last one of pair of tie wings includes a recess or area of reduced thickness to facilitate flexing of the at least one pair of tie wings to permit insertion or removal of an archwire through an opening between the tie wings relative to an archwire guide slot, afterwhich the tie wings close relative to one another.

It is also an object of the invention to provide self-ligating orthodontic brackets that are formed at least partially of a shape memory material and that include at least one tie wing that can be moved to permit insertion and/or removal of an archwire between tie wing posts and thereafter recover to a predetermined position. At least one tie wing post includes a flange which extends toward an opposing tie wing post to thereby normally retain an archwire within the archwire guide slot defined between the tie wing posts.

It is another object of the present invention to provide nickel-titanium orthodontic brackets that include a pair of opposing tie wings, each of which defines an archwire slot therebetween. The tie wings are spaced relative to each other so that each bracket may be used in an initial position for treatment wherein an archwire may only pass through one tie wing and thereafter may be adjusted such that the archwire passes through the guide slots of both tie wings as treatment progresses.

It is yet a further object of the present invention to provide nickel-titanium or other shape memory type orthodontic brackets which may be coated with metallic or non-metallic materials in such a manner as to reduce friction to thereby further facilitate the sliding movement of an archwire relative to the brackets during patient treatment and/or to enhance aesthetics.

It is also an object of the present invention to enhance the aesthetic appearance of orthodontic brackets by providing nickel-titanium alloy or other shape memory material orthodontic brackets which may be coated in various colors to promote style depending on patient preferences.

The flexibility of the nickel-titanium or other shape memory self-ligating brackets with their small compact design makes them easier to use in the small confines of a patient's mouth which will give the orthodontist additional treatment options of using ligatures, additional attachments, and/or auxiliaries to hold archwires in place in the bracket slots. Thus, these brackets solve the limitations of current self-ligating brackets.

The small compact flexible tie wings of the brackets of the invention, with and without a coating, will permit orthodontists to overcome the many challenges they face during treatment and alignment of a patient's teeth. Thus, the orthodontic brackets of the present invention will make the patient's visits to the orthodontist to have their braces adjusted a much less complicated process and overall more comfortable and quicker, resulting in making the overall treatment experience a more pleasant one while achieving superior results for the patient.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the invention will be had with reference to the accompanying drawings wherein;

FIG. 1 is a front perspective view of a twin bracket embodiment of an orthodontic bracket of the present invention;

FIG. 2A is a side elevational view of the twin bracket of FIG. 1, showing both opposing tie wings being unflexed before insertion of an archwire relative to a guide slot defined between a pair of opposing tie wing posts of each of the tie wings of the bracket;

FIG. 2B is a side elevational view of the twin bracket of FIG. 1, showing both opposing tie wing posts flexing to permit insertion of an archwire therebetween;

FIG. 2C is a side elevational view of the twin bracket of FIG. 2A with an archwire seated within the archwire guide slot after the tie wings have returned back to their initial positions shown in FIG. 2A;

FIG. 3A is a view similar to 2A, except only one tie wing post of each tie wing is formed of a shape memory material and except one inner flange of the pair of tie wing posts is larger than the opposing inner flange;

FIG. 3B is a side elevational view of the twin bracket of FIG. 3A showing only one tie wing post of each tie wing being flexed to permit insertion of an archwire within the guide slot between the opposing tie wing posts of each tie wing;

FIG. 3C is a side elevational view of the twin bracket of FIG. 3A showing the archwire seated in the slot between the tie wing posts after the tie wing posts have returned back to their initial positions shown in FIG. 3A;

FIG. 4 is a side elevational view of a modified form of the twin bracket shown in FIGS. 3A-3C where only one tie wing post includes an inner flange;

FIG. 5 is a front perspective view of another twin bracket embodiment of an orthodontic bracket according to the invention;

FIG. 6 is a front perspective view of a further twin bracket embodiment of an orthodontic bracket in accordance with the invention;

FIG. 7 is a front perspective view of an additional twin bracket embodiment of an orthodontic bracket in accordance with the invention;

FIG. 8A is a front perspective view of a single wing bracket embodiment of an orthodontic bracket according to the invention, showing an identification recess on one tie wing;

FIG. 8B is a front perspective view of a modified form of the bracket shown in FIG. 8A;

FIG. 9 is a top elevational view of the bracket of FIG. 8A;

FIG. 10A is a front perspective view of a single wing Lewis-type bracket embodiment of an orthodontic bracket according to the invention, showing an identification recess on one tie wing;

FIG. 10B is a front perspective view of a modified form of the Lewis-type bracket shown in FIG. 10A;

FIG. 11 is a side elevational view of the Lewis-type bracket of FIG. 10A, showing both opposing tie wing posts being unflexed before insertion of an archwire relative to a guide slot defined between opposing tie wing posts of the bracket;

FIG. 12A is a front perspective view of a single wing Lang-type bracket embodiment of an orthodontic bracket according to the invention;

FIG. 12B is a front perspective view of a modified form of the Lang-type bracket shown in FIG. 12A;

FIG. 13 is a top elevational view of the Lang-type bracket of FIG. 12A;

FIG. 14A is a front perspective view of a single wing Creekmore-type bracket embodiment of an orthodontic bracket according to the invention;

FIG. 14B is a front perspective view of a modified form of the Creekmore-type bracket shown in FIG. 14A;

FIG. 15 is a side elevational view of the Creekmore-type bracket of FIG. 14A, showing both opposing tie wing posts being unflexed before insertion of an archwire relative to a guide slot defined between opposing tie wing posts of the bracket;

FIG. 16A is a front perspective view of the twin bracket of FIG. 1 having a central recess, a vertical scribe line, a hook, and identification recesses on one tie wing post of each tie wing;

FIG. 16B is a front perspective view of a modified form of the twin bracket of FIG. 16A having a central recess, a vertical scribe line, and an identification recess on one tie wing;

FIG. 17A is a front perspective view of a modified form of the twin bracket of FIG. 1 having a central recess, a vertical scribe line, a hook, and an identification recess on one tie wing;

FIG. 17B is a front perspective view of a modified form of the twin bracket of FIG. 17A having a central recess, a vertical scribe line and an identification recess on one tie wing post of each tie wing;

FIG. 18A is a front perspective view of a modified form of the twin bracket of FIG. 1 having a central recess, a vertical scribe line, a vertical slot, and an identification recess on one tie wing post of one tie wing of the bracket;

FIG. 18B is a front perspective view of a modified form of the twin bracket of FIG. 18A having a central recess, a vertical scribe line, a vertical slot, and an identification recess on one tie wing;

FIG. 18C is a side elevational view of the twin bracket of FIG. 18A;

FIG. 19 is a front perspective view of a modified form of the twin bracket of FIG. 18A having a vertical scribe line, a vertical slot, and an identification recess on one tie wing post of one tie wing of the bracket;

FIG. 20A is a front perspective view of a hybrid bracket embodiment of the invention having an identification recess on one tie wing of the bracket;

FIG. 20B is a front perspective view of a modified form of the hybrid bracket of FIG. 20A;

FIG. 20C is another top perspective view of the hybrid bracket of FIG. 20A;

FIG. 21 is a rear perspective view of the twin bracket of FIG. 1 showing a mesh base;

FIG. 22A is a front perspective view of a torque-in-base configuration of the twin bracket of FIG. 1 having a vertical scribe line, a hook, and an identification recess on one tie wing;

FIG. 22B is a front perspective view of a modified form of the torque-in-base twin bracket of FIG. 22A;

FIG. 22C is a side elevational view of the torque-in-base twin bracket of FIG. 22A;

FIG. 23A is a front perspective view of a torque-in-slot configuration of the twin bracket of FIG. 1 having a vertical scribe line, a hook, and an identification recess on one tie wing;

FIG. 23B is a front perspective view of a modified form of the torque-in-slot twin bracket of FIG. 23A; and

FIG. 23C is a side elevational view of the torque-in-slot twin bracket of FIG. 23A.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1-2C, 16A, and 21, a twin bracket embodiment of orthodontic bracket 10 of the present invention comprises a unitary body structure including a contoured base 12 having a front surface 13 and a rear tooth engaging surface 14. The rear surface 14 is generally slightly concavely contoured so as to match the surface contour of a patient's tooth.

The rear surface 14 has a bonding pad with a mesh 15, as shown in FIG. 21, such that the bracket 10 may be bonded securely to a patient's tooth or welded to a band cemented to the tooth. The mesh 15 is preferably a 80-100 gauge mesh. As an alternative to the mesh 15, the rear surface 14 may include a plurality of grooves or mechanical undercuts to ensure the bracket 10 can be securely bonded to a patient's tooth. Further, a bonding strength of the bond between the mesh 15, grooves, and/or undercuts and a tooth may be enhanced by a micro-etching process.

The orthodontic bracket 10 further includes a pair of spaced opposing tie wings 20 and 21 which are shown as being spaced on opposite sides of a central recess 17 which is formed generally centrally of the front surface 13 of the bracket base 12. The recess 17 is used to facilitate alignment of the bracket 10 relative to a patient's tooth using an instrument such as a Boone gauge. Further, a linear groove, such as a vertical scribe line 42, may be also provided in the front surface 13 of the bracket base 12 for facilitating alignment, such as shown in FIG. 16A. Further, both the recess 17 and the vertical scribe line 42 can be used with other embodiments of the invention.

The bracket 10 may also include auxiliary attachments, such as Kobayashi hooks, removeable hook pins, ligature wires, directional force elastics, elastomeric ligatures, elastomeric power chains, and uprighting springs, which are often used during various stages of orthodontic treatment. These attachments can be secured to various parts of a bracket, including slots, such as vertical slots, and tie wings. As shown in FIG. 16A, the bracket 10 includes a hook 44 which is secured to the tie wing 20. Auxiliary attachments, such as the hook 44, can be used with other embodiments of the invention.

The bracket 10 may also include one or more color-coded identification recesses 46, as shown in FIG. 16A. The identification recess 46 is a small depression which is often filled with a colored material. The identification recess enables an orthodontist to determine how the bracket 10 should be positioned on a patient's tooth. For example, a yellow identification recess may indicate the portion of the bracket 10 which should be placed on the distal gingival edge of a tooth. Further, the identification recess 46 can be used with other embodiments of the invention.

Each of the tie wings 20 and 21 includes a base portion 18 from which extend a pair of tie wing posts 22 and 23. Each of the tie wing posts 22 and 23 includes an upper head portion 24 and 25, respectively. Each pair of the generally parallel posts 22 and 23 define an archwire guide slot 26 of approximately 0.018 to 0.022 inch therebetween to slidingly engage an archwire 30.

The shape memory brackets of the present invention are self-ligating. That is, at least one of the posts of one tie wing is formed of a shape memory material. In the embodiment shown in FIGS. 1-2C, both of the opposing pair of tie wings 20 and 21 are formed of a material which allows the tie wings 20 and 21 to flex, as shown and illustrated in FIG. 2B, to permit insertion or removal of the archwire 30 relative to the guide slot 26. In preferred embodiments, brackets of the present invention are formed of a shape memory material, such as a nickel-titanium material, both along the base 12 and the tie wings 20 and 21. This material exhibits superelasticity and, therefore, shape memory, such that when the posts 22 and 23 are flexed from a predetermined or rest position, as shown in FIG. 2A, the head portions 24 and 25 of each tie wing separate, as shown in FIG. 2B, to permit the insertion or removal of the archwire 30. Once force is removed, the posts 22 and 23 return to their original predetermined position, as shown in FIG. 2C. Shape memory materials, such as metallic materials, including alloys, and non-metallic materials, including resins and polymer-type materials, that exhibit a shape memory may be used.

To securely retain an archwire 30 within the guide slot 26, each head portion 24 and 25 of each tie wing post 22 and 23, respectively, as shown in FIG. 2A, includes an inner opposing flange 31 and 32, respectively. The inner flanges 31 and 32 are spaced at a distance “D” of approximately 0.010-0.014 inch which is smaller than the diameter of the archwire 30. In some embodiments, the flanges 31 and 32 may actually touch one another such that the distance “D” is zero. Further, the inner flanges 31 and 32 may be the same size, as shown in FIGS. 2A-2C.

Each head portion 24 and 25 of each tie wing post 22 and 23, respectively, further includes an outer tie wing flange 34 and 35, respectively, which may be used in a conventional manner to secure archwires with ligature wires and other attachments during patient treatment, as necessary. In the preferred embodiments, the entire outer surface of each of the head portions 24 and 25 is shown as being generally convex with the inner flanges 31 and 32, respectively, tapering downwardly and inwardly relative to one another.

As opposed to each tie wing 20 and 21 including a base portion, such as illustrated at 18, it is possible that the tie wings 20 and 21 are formed such that the posts extend upwardly from the front surface 13 of the bracket base 12.

An alternate embodiment of the invention is shown in FIGS. 3A-3C. In this embodiment, only one tie wing post or a portion of one tie wing post of each pair of tie wing posts 22′ and 23′ of opposing pair of tie wings 20′ and 21′ is formed of a shape memory material so as to be flexed from a predetermined or rest position, as shown on FIG. 3A, to a spaced position, as shown by the arrow in FIG. 3B, to permit insertion or removal of the archwire 30 relative to an archwire slot 26′. Thereafter, the tie wing post or portion of the tie wing post will return to the predetermined or rest position, as shown in a FIG. 3C. The bracket 10′ of this embodiment is otherwise the same as the bracket 10 previously described. Accordingly, the bracket 10′ includes a bracket base 12′ and a pair of opposing tie wings 20′ and 21′. Each of the tie wings 20′ and 21′ includes tie wing posts 22′ and 23′ having head portions 24′ and 25′, respectively. Further each of the head portions 24′ and 25′ include an inner opposing flange 31′ and 32′, respectively, and an outer flange 34′ and 35′, respectively.

The inner flanges 31′ and 32′ define an opening “D,” as previously defined. Also, the inner flanges one of the inner flanges 31′ and 32′ may be larger than an opposing inner flange, as shown in FIGS. 3A-3C.

A modification of the twin orthodontic bracket shown in FIGS. 3A-3C is shown in FIG. 4. In this embodiment, only one tie wing post 22′ of each pair of opposing tie wing posts 22′ and 23′ of each of the tie wings 20′ and 21′ includes an inner flange 31′ which defines the opening “D,” as previously defined. As shown, there is no inner flange associated with tie wing post 23′. The functioning of the bracket 10′ is otherwise the same as described with respect to FIGS. 3A-3C.

As illustrated in FIG. 5, to further promote the flexing of a tie wing and/or wings, grooves, such as shown at 37, may be provided adjacent to the inner portion of each of the tie wing posts 22A and 23A. This facilitates a flexing of the tie wings 20A and 21A at the area of reduced thickness. A bracket 10A of this embodiment is shown as being smaller than that of the embodiment of FIG. 1, such that the opposing pair of tie wings 20A and 21A are more closely spaced. The bracket 10A includes a base 12A and tie wings 20A and 21A defining archwire guide slots 26A therebetween. The provision of a groove 37 to promote flexing may also be used in other embodiments of the invention.

As shown in FIG. 7, to achieve additional flexing of the tie wing and/or tie wings, the thickness of the tie wing posts 22C and 23C may be reduced in an area, such as shown at 38. The bracket 10C of this embodiment is shown as being smaller than that of the embodiment of FIG. 1 such that the opposing pair of tie wings 20C and 21C are more closely spaced. The bracket 10C includes a base 12C and tie wings 20C and 21C defining archwire guide 26C therebetween. The provision of reduced thickness of the tie wing posts 22C and 23C to achieve additional flexing may also be used in other embodiments of the invention.

As an alternative to the embodiment of the twin bracket shown in FIG. 7, another embodiment to promote flexing of a tie wing and/or tie wings is shown in FIG. 16B. Instead of the thickness of the tie wing posts being reduced in a limited area, a bracket 10D includes a pair of opposing tie wings 20D and 21D, each having a pair of tie wing posts 22D and 23D, respectively, that each have an outer concave surface 39. The concave outer surface 39 of each of the tie wing posts 22D and 23D essentially provides areas of reduced thickness so as to provide additional flexing of the tie wings 20D and 21D.

Like the bracket 10 shown in FIGS. 1-2C and 16A, the bracket 10D includes a base 12D and a pair of tie wings 20D and 21D defining archwire guide slots 26D therebetween. The -bracket 10D also includes a central recess 17, a vertical scribe line 42, and a identification recess 46 located on one of the tie wings to aid in positioning the bracket 10D on a patient's tooth. The provision of a concave surface 39 to promote flexing may also be used in other embodiments of the invention.

The bracket of the invention can also be designed to provide various torques, angulations, and in/out thickness variations, which are useful during orthodontic treatments. Torque-in-base and slot angulation, which are illustrated in FIGS. 22A-22C, and torque-in-slot and slot angulation, which are illustrated in FIGS. 23A-23C, and in/out thickness variations, such as shown in FIG. 19, are examples of a such bracket designs. Further, the provisions for providing torques, angulations, and in/out thicknesses can be used with the various embodiments of the present invention.

In a torque-in-base and slot angulation configuration shown in FIGS. 22A-22C, a twin bracket 10″ includes a contoured base 12″ and a pair of spaced opposing tie wings 20″ and 21″ which are shown as being spaced on opposite sides of a central recess 17 which is formed generally centrally of the bracket base 12″. The bracket 10″ also includes a vertical scribe line 42, a hook 44, and a color-coded identification recess on each of the tie wings 20″ and 21″.

Each of the tie wings 20″ and 21″ includes a base portion 18″ from which extend tie wings a pair of tie wing posts 22″ and 23″. Each of the tie wing posts 23″ and 24″ include an upper head portion 24″ and 25″, respectively. Each pair of the generally parallel posts 22″ and 23″ define an archwire guide slot 26″ to slidingly engage an archwire.

In a torque-in-base and slot angulation configuration, the heights, namely the distances between the bracket base 12″ and the head portions 24″ and 25″, and angles of each of the tie wing posts 22″ and 23″, respectively, are different. As shown in FIGS. 22A-22C, tie wing post 22″ is higher than tie wing post 23″ so as to provide a torque to a patient's tooth when the bracket 10″ engages an archwire.

FIG. 22B shows a modified form of the bracket 10″ shown in FIGS. 22A and 22C. The bracket configuration of FIG. 22B promotes flexing of a tie wing and/or tie wings. Each of the tie wing posts 22″ and 23″ have an outer concave surface 39 to provide additional flexing of the tie wings 20″ and 21″.

In a torque-in-slot and slot angulation configuration, the depths and angles, namely the distances between the base 12″ and the head portions 24″ and 25″ of each of the tie wing posts 22″ and 23″, respectively, of portions of the guide slot 26″ are different. As shown in FIGS. 23A-23C, a portion of the guide slot 26″ adjacent tie wing post 23″ is deeper than a portion of the guide slot 26″ adjacent the tie wing post 22″ so as to provide a torque on a patient's tooth when the bracket 10″ engages an archwire.

Like FIG. 22B, FIG. 23B shows a modified form of the bracket 10″ shown in FIGS. 23A and 23C. The bracket configuration of FIG. 23B promotes flexing of a tie wing and/or tie wings. Each of the tie wing posts 22″ and 23″ have an outer concave surface 39 to provide additional flexing of the tie wings 20″ and 21″.

Whether utilizing a torque-in-base or torque-in-slot configuration, an angle of the archwire guide slot can be adjusted to accommodate different tooth variations. Since the angulation is in the archwire guide slot, a use of a rhomboidal design of the bracket exterior is useful to ensure that the archwire guide slot aligns with a guide slot of an adjacent bracket.

In a variation of in/out thickness, the heights, namely the distances between a bracket base and an archwire guide slot, and angles vary to compensate for different tooth sizes. For example, the height of a bracket 10G shown in FIG. 19 is larger than the bracket 10 shown in FIG. 1 so that the bracket 10G has a different in/out thickness than the bracket 10 of FIG. 1.

With reference to FIG. 6, another embodiment of the invention is shown. In this embodiment, a bracket 10B is formed of the same shape memory material and has a pair of opposing tie wings 20B and 21B which extend from a base 12B. However, the tie wings 20B and 21B are attached directly to the bracket base 12B and extend upwardly from a position more closely spaced to a gingival edge 40 of the bracket base 12B. This structure permits correct bonding of brackets on short or gingivally displaced teeth. In this embodiment, a horizontal recess alignment guide 40 is shown, as opposed to the recess 17, shown in FIG. 1. In this embodiment, either one or both of the opposing tie wings 20B and 21B may be flexed as previously described.

Another twin bracket embodiment of the invention is shown in FIGS. 17A and 17B. Similar to the embodiment shown in FIGS. 1-2C and 16A, a bracket 10E, as shown in FIG. 17A, includes a contoured base 12E having a front surface 13E and a rear tooth engaging surface 14E. The rear surface 14E is generally slightly concavely contoured so as to match the surface contour of a patient's tooth.

The orthodontic bracket 10E further includes a pair of spaced opposing tie wings 20E and 21E which are shown as being spaced on opposite sides of a central recess 17, which is formed generally centrally of the front surface 13E of the bracket base 12E. Unlike the embodiment shown in FIGS. 1-2C and 16A, the bracket 10E also includes a platform 50 which is secured to the base 12E and extends between the tie wings 20E and 21E. Each of the tie wings 20E and 21E includes a base portion 18E attached the platform 50. Preferably, the width of the platform 50 is the same as the width of the base portion 18E of each of the tie wings 20E and 21E.

The tie wings 20E and 21E each include a pair of tie wing posts 22E and 23E. Each of the tie wing posts 22E and 23E include an upper head portion 24E and 25E, respectively. Each pair of the generally parallel posts 22E and 23E define an archwire guide slot 26E therebetween to slidingly engage an archwire.

The twin bracket 10E can also include auxiliary attachments and positioning aids. As shown in FIG. 17A,.the bracket 10E includes a hook 44 and a color-coded identification recess 46 located on one of the tie wings 20E and 21E. The bracket 10E also includes a central recess 17 and a vertical scribe line 42.

A modified form of the twin bracket shown in FIG. 17A is shown in FIG. 17B. A bracket 10E′ is designed to promote flexing of a tie wing and/or tie wings. The bracket 10E′ includes a bracket base 12E′ and a pair of opposing tie wings 20E′ and 21E′, each having a pair of tie wing posts 22E′ and 23E′ forming an archwire guide slot 26E′ therebetween. The bracket 10E′ is similar to the bracket 10E, except each of the tie wing posts 22E′ and 23E′ have an outer concave surface 39 to provide additional flexing of the tie wings 20E′ and 21E′. Further, the bracket 10E′ includes an identification recess on each of the tie wings 20E′ and 21E′.

A further twin bracket embodiment of the invention is shown in FIGS. 18A-18C. Similar to the embodiment shown in FIGS. 1-2C and 16A, a bracket 10F, as shown in FIGS. 18A and 18C, includes a contoured base 12F having a front surface 13F and a rear tooth engaging surface 14F. The orthodontic bracket 10F further includes a pair of spaced opposing tie wings 20F and 21F which are shown as being spaced on opposite sides of a central recess 17, which is formed generally centrally of the front surface 13F of the bracket base 12F.

Unlike the embodiment shown in FIGS. 1-2C and 16A, the bracket 10F also includes a platform 60 which is secured to the base 12F and extends between the tie wings 20F and 21F. Each of the tie wings 20F and 21F includes a base portion 18F attached the platform 60. Preferably, the width of the platform 60 is the same as the width of the base portion 18F of each of the tie wings 20F and 21F. While the twin bracket 10E shown in FIGS. 17A and 17B also utilizes a platform 50, the platform 60 of bracket 10F is preferably higher than the platform 50 of the bracket 10E and includes a vertical slot 62 passing therethrough, as shown in FIG. 18C.

Like the bracket 10 shown in FIGS. 1-2C and 16 and the bracket 10E shown in FIGS. 17A and 17B, the tie wings 20F and 21F of the bracket 10F each include a pair of tie wing posts 22F and 23F. Each of the tie wing posts 22F and 23F include an upper head portion 24F and 25F, respectively. Each pair of the generally parallel posts 22F and 23F define an archwire guide slot 26F therebetween to slidingly engage an archwire.

The twin bracket 10F can also include auxiliary attachments and positioning aids. As shown in FIG. 18A, the bracket 10F includes a color-coded indication recess 46 located on the head portion of one tie wing post of one of the tie wings 20F and 21F. The bracket 10F also includes a central recess 17 and a vertical scribe line 42.

A modified form of the twin bracket shown in FIG. 18A is shown in FIG. 18B. A bracket 10F′ is designed to promote flexing of a tie wing and/or tie wings. The bracket 10F′ includes a bracket base 12F′ and a pair of opposing tie wings 20F′ and 21F′, each having a pair of tie wing posts 22F′ and 23F′ forming an archwire guide slot 26F′ therebetween. The bracket 10F′ is similar to the bracket 10F, except each of the tie wing posts 22F′ and 23F′ have an outer concave surface 39 to provide additional flexing of the tie wings 20F′ and 21F′.

Yet another twin bracket embodiment of the invention is shown in FIG. 19. Similar to the embodiment shown in FIGS. 18A and 18C, a bracket 10G, includes a contoured base 12G having a front surface 13G and a rear tooth engaging surface 14G. The orthodontic bracket 10G further includes a pair of spaced opposing tie wings 20G and 21G which are shown as being spaced on opposite sides of a vertical scribe line 42.

The bracket 10G also includes a platform 70 which is secured to the base 12G and extends between the tie wings 20G and 21G. Preferably, the width of the platform 70 is the same as the width tie wings 20G and 21G, and the platform 70 includes a vertical slot 72 passing therethrough.

Unlike the bracket 10F, the tie wings 20G and 21G of the bracket 10G each include a pair of tie wing posts 22G and 23G which extend directly from the platform 70. The tie wings 20G and 21G do not include any base portion. Each of the tie wing posts 22G and 23G include an upper head portion 24G and 25G, respectively. Each pair of the generally parallel posts 22G and 23G define an archwire guide slot 26G therebetween to slidingly engage an archwire.

Like the other embodiments of the invention, the twin bracket 10G can also include auxiliary attachments, color-coded identification recesses, and positioning aids. As shown in FIG. 19, the bracket 10G includes a color-coded identification recess 46 located on the head portion of one tie wing post of one of the tie wings 20G and 21G.

With the structure of the twin embodiments of the present invention, it is possible to apply the bracket to extremely twisted or crooked teeth wherein only a single tie wing may be appropriately aligned with the tooth to receive an archwire. During treatment, the archwire may be seated within a single guide slot defined by one tie wing until such a time as a tooth can be moved to a position wherein the archwire may be aligned in the bracket slots of both tie wings. In this respect, the tie wings of the twin bracket embodiments of the invention define guide slots which are preferably axially aligned relative to one another along a line A-A as shown in FIG. 1.

In addition to a double tie wing configuration, the self-ligating bracket of the present invention may also be a single wing bracket. Further, many of the features set forth in the description of the twin bracket embodiments are applicable to the single wing and other embodiments of the present invention.

With reference to FIGS. 8A-9, a single wing orthodontic bracket 110, as specifically shown in FIGS. 8A and 9, comprises a unitary body structure including a contoured base 112 having a front surface 113 and a rear tooth engaging surface 114. The rear surface 114 is generally slightly concavely contoured so as to match the surface contour of a patient's tooth. The rear surface 114 has a bonding pad with a mesh so that the bracket 110 may be bonded securely to a patient's tooth or welded to a band cemented to the tooth. As previously described, the mesh is preferably of a 80-100 gauge mesh. As an alternative to the mesh, the rear surface 114 may include a plurality of grooves and/or mechanical undercuts to ensure the bracket 110 can be secured to a patient's tooth. Further, a bond strength between the mesh, grooves, and/or undercuts and a tooth can be enhanced by a micro-etching process.

The bracket 110 may also include auxiliary attachments, such as Kobayashi hooks, removeable hook pins, metal ligatures, directional force elastics, elastomeric ties, elastomeric power chains, and uprighting springs, which are often used during various stages of orthodontic treatment. These attachments can be secured to various parts of a bracket, including slots, such as vertical slots, and tie wings, and can be used with other embodiments of the invention.

The bracket 110 may also include one or more color-coded identification recesses 46. As set forth above, the identification recess 46 is a small depression which is often filled with a colored material. The identification recess enables an orthodontist to determine how the bracket 110 should be positioned on a patient's tooth. The identification recess 46, as well as other positioning aids, such as a central recess and a vertical or horizontal scribe line, can be used with other embodiments of the invention.

The orthodontic bracket 110 further includes a tie wing 120 having a base portion 18 from which extend a pair of tie wing posts 122 and 123. Alternatively, as opposed to the tie wing 120 including a base portion, such as illustrated at 118, it is possible that the tie wing 120 is formed such that the posts 122 and 123 extend upwardly from the front surface 113 of the bracket base 112. Each of the tie wing posts 122 and 123 includes an upper head portion 124 and 125, respectively. Each pair of the generally parallel posts 122 and 123 define an archwire guide slot 126 of approximately 0.018 to 0.022 inch therebetween to slidingly engage an archwire.

As stated above, the shape memory brackets of the present invention are self-ligating. With regard to the single wing embodiments, at least one of the tie wing posts, or a portion thereof, is formed of a shape memory material. In the embodiment shown in FIGS. 8A-9, both of the opposing tie wing posts 122 and 123 of the tie wing 120 are formed of a material which allows the tie wing 120 to flex to permit insertion or removal of the archwire relative to the guide slot 126.

In preferred embodiments, brackets of the present invention are formed of a shape memory metallic material, including alloys, such as a nickel-titanium material, or from a shape memory non-metallic material, including resins and polymer materials, both along the base 112 and the tie wing 120. This material exhibits super-elasticity and, therefore, shape memory, such that when the posts 122 and 123 are flexed from a predetermined or rest position, the head portions 124 and 125 of each tie wing post separate to permit the insertion or removal of the archwire. Once force is removed, the posts 122 and 123 return to the original predetermined positions.

To securely retain an archwire within the guide slot 126, each head portion 124 and 125 of each tie wing post 122 and 123, respectively, includes an inner opposing flange 131 and 132, respectively. The inner flange 131 and 132 are spaced at a distance “D” of approximately 0.010-0.014 inch which is smaller than the diameter of the archwire. In some embodiments, the flange 131 and 132 may actually touch one another such that the distance “D” is zero. Further, the inner flange 131 and 132 may be the same or different sizes.

Each head portion 124 and 125 of each tie wing post 122 and 123, respectively, further includes an outer tie wing fLang-typee 134 and 135, respectively, which may be used in a conventional manner to secure archwires with ligature wires and other attachments during patient treatment, as necessary. In the preferred embodiments, the entire outer surface of each of the head portions 124 and 125 is shown as being generally convex with the inner flange 131 and 132, respectively, tapering downwardly and inwardly relative to one another.

As an alternative to the embodiment of the single wing bracket shown in FIGS. 8A and 8C, another embodiment to promote flexing of a tie wing is shown in FIG. 8B. A bracket 110′ includes a base 112′ and a tie wing 1201 having a pair of opposing tie wing posts 122′ and 123′ that each have an outer concave surface 39. Thus, the bracket 110′ is essentially the same as the bracket 110 but includes tie wing posts 122′ and 1231 having concave outer surfaces 39. The concave outer surface 39 of each of the tie wing posts 122′ and 123′ essentially provides areas of reduced thickness so as to provide additional flexing of the tie wing 120′.

A Lewis-type single wing bracket embodiment of the invention is shown in FIGS. 10A-11. The Lewis-type configuration can also be used in a twin bracket. A bracket 210, as shown in FIGS. 10A and 11, includes a contoured base 212 and a tie wing 220 having a base portion 218 from which extend a pair of tie wing posts 222 and 223. Each of the tie wing posts 222 and 223 includes an upper head portion 224 and 225, respectively. Each pair of the generally parallel posts 222 and 223 define an archwire guide slot 226 to slidingly engage an archwire 30.

The Lewis-type bracket 210 also includes a platform 240 which extends across a width of the base 212 along an axial line A-A. Instead of the base portion 218 of the tie wing 220 being directly attached to the bracket base 212, the base portion 218 is secured to the platform 240 so that the archwire guide slot 226 is elevated from the bracket base 212 a distance equal to the combined heights of the tie wing base 218 and the platform 240, not just the height of the tie wing base 218.

The width of the platform 240 is greater than the width of the bracket base 212 along the line A-A. As a result, the platform 240 forms a tab 242 projecting from either side of the tie wing base portion 218 along the line A-A. Further, each tab 242 is bent upwardly toward the head portions 224 and 225 of the tie wing posts 222 and 223, respectively.

At least one of the tie wing posts 222 and 223, or a portion thereof, is preferably formed from a shape memory material, such that when the post is flexed from a predetermined or rest position, shown in FIG. 11, the head portions 224 and 225 of each tie wing separate to permit the insertion or removal of the archwire 30. Once force is removed, the post returns to the original predetermined position.

To securely retain the archwire 30 within the guide slot 226, each head portion 224 and 225 of each of the tie wing posts 222 and 223, respectively, includes an inner opposing flange 231 and 232, respectively, and an outer tie wing flange 234 and 235, respectively. The Lewis-type bracket 210 also includes a color-coded identification recess 46 located on one of the tie wings.

A modified form of the Lewis-type bracket is shown in FIG. 10B. A bracket 210′ is designed to promote flexing of a tie wing. The bracket 210′ includes a bracket base 212′ and a tie wing 220′ having a pair of tie wing posts 222′ and 223′ forming an archwire guide slot 326′ therebetween. The bracket 210′ also includes a platform 240′ which extends across the bracket base 212′ to form an upwardly bent tab 242′ on either side of the tie wing 220′. The bracket 210′ is similar to the bracket 210, except each of the tie wing posts 222′ and 223′ have an outer concave surface 39 to provide additional flexing of the tie wing 220′.

A Lang-type single wing bracket embodiment of the invention is shown in FIGS. 12A-13. The Lang-type configuration can also be used in a twin bracket. A bracket 310, as shown in FIGS. 12A and 13, includes a contoured base 312 and a tie wing 320 having a base portion 318 from which extend a pair of tie wing posts 322 and 323. Each of the tie wing posts 322.and 323 includes an upper head portion 324 and 325, respectively. Each pair of the generally parallel posts 322 and 323 define an archwire guide slot 326 to slidingly engage an archwire, and at least one of the tie wing posts 322 and 323, or a portion thereof, is preferably formed from a shape memory material. Further, to securely retain the archwire within the guide slot 326, each head portion 324 and 325 of each of the tie wing posts 322 and 323, respectively, includes an inner opposing flange 331 and 332, respectively, and an outer tie wing flange 334 and 335, respectively.

The bracket 310 also includes a platform 340 which extends across a width of the base 312 along an axial line A-A. Instead of the base portion 318 of the tie wing 320 being directly attached to the bracket base 312, the base portion 318 is secured to the platform 340 so that the archwire guide slot 326. Further, the width of the platform 340 is greater than the width of the bracket base 312 along the line A-A. As a result, the platform 340 forms a tab 342 projecting from either side of the tie wing base portion 318 along the line A-A. Each tab 342 includes an opening 343 formed therein.

A modified form of the Lang-type bracket is shown in FIG. 12B. A bracket 310′ is designed to promote flexing of a tie wing. The bracket 310′ includes a bracket base 312′ and a tie wing 320′ having a pair of tie wing posts 322′ and 323′ forming an archwire guide slot 326′ therebetween. The bracket 310′ also includes a platform 340′ which extends across the bracket base 312′ to form a tab 342′ with an opening 343′ on either side of the tie wing 320′. The bracket 310′ is similar to the bracket 310, except each of the tie wing posts 322′ and 323′ have an outer concave surface 39 to provide additional flexing of the tie wing 320′.

A Creekmore-type single wing bracket embodiment of the invention is shown in FIGS. 14A-15. The Creekmore-type configuration can also be used with a twin bracket. A bracket 410, as shown in FIGS. 14A and 15, includes a contoured base 412 and a tie wing 420 having a base portion 418 from which extend a pair of tie wing posts 422 and 423. The bracket 410 also includes a curled tab 442 projecting from either side of the bracket base 312 along an axial line A-A of the bracket 410.

Each of the tie wing posts 422 and 423 includes an upper head portion 424 and 425, respectively. Each pair of the generally parallel posts 422 and 423 define an archwire guide slot 426 to slidingly engage an archwire 30. At least one of the tie wing posts 422 and 423, or a portion thereof, is preferably formed from a shape memory material, such that when the post is flexed from a predetermined or rest position, shown in FIG. 15, the head portions 424 and 425 of each tie wing separate to permit the insertion or removal of the archwire 30. Once force is removed, the post returns to the original predetermined position. Further, to securely retain the archwire 30 within the guide slot 426, each head portion 424 and 425 of each of the tie wing posts 422 and 423, respectively, includes an inner opposing flange 431 and 432, respectively, and an outer tie wing flange 434 and 435, respectively.

A modified form of the Creekmore-type bracket is shown in FIG. 14B. A bracket 410′ is designed to promote flexing of a tie wing. The bracket 410′ includes a bracket base 412′ and a tie wing 420′ having a pair of tie wing posts 422′ and 423′ forming an archwire guide slot 426′ therebetween. The bracket 410′ also includes a curled tab 442′ on either side of the bracket base 412′. The bracket 410′ is similar to the bracket 410, except each of the tie wing posts 422′ and 423′ have an outer concave surface 39 to provide additional flexing of the tie wing 420′.

In addition to double tie wing configurations and single tie wing designs, the self-ligating bracket of the present invention may also be a hybrid bracket. A hybrid bracket appears to have two tie wings, but the two tie wing structures are actually part of a single unitary structure. Thus, a hybrid bracket imparts characteristics of both single wing and double wing bracket configurations. Further, many of the features set forth in the description of the twin bracket and single wing bracket embodiments are applicable to the hybrid embodiments of the present invention.

With reference to FIGS. 20A-20C, a hybrid wing orthodontic bracket 510, as specifically shown in FIGS. 20A and 20C, comprises a unitary body structure including a contoured base 512 having a front surface 513 and a rear tooth engaging surface 514. The rear surface 514 is generally slightly concavely contoured so as to match the surface contour of a patient's tooth.

The rear surface 514 has a bonding pad with a mesh so that the bracket 510 may be bonded securely to a patient's tooth or welded to a band cemented to the tooth. As previously described, the mesh is preferably a 80-100 gauge mesh. As an alternative to the mesh, the rear surface 514 may include a plurality of grooves and/or mechanical undercuts to ensure the bracket 510 can be secured to a patient's tooth. Further, a bond strength between the mesh 15, grooves, and/or mechanical undercuts and a tooth can be enhanced by a micro-etching process.

The bracket 510 may also include auxiliary attachments, such as Kobayashi hooks, hooks, such as hook 44 shown in FIG. 20C, removeable hook pins, metal ligatures, directional force elastics, elastomeric ligature, elastomeric power chains, and uprighting springs, which are often used during various stages of orthodontic treatment. These attachments may be integrally formed with the bracket or removeable therefrom. Further, these attachments can be secured to various parts of a bracket, including slots, such as vertical slots, and tie wings, and can be used with other embodiments of the invention. The bracket 510 may also include one or more color-coded identification recesses. As set forth above, the identification recess is a small depression which is often filled with a colored material. The identification recess enables an orthodontist to determine how the bracket 510 should be positioned on a patient's tooth. The identification recess, as well as other positioning aids, such as a central recess and a vertical or horizontal scribe line, can be used with other embodiments of the invention.

The orthodontic bracket 510 further includes a single elongated tie wing 520 having a base portion 518 from which extend two pair of tie wing posts 522 and 523 on either end of the bracket 510. Each pair of the tie wing posts 522 and 523 includes an upper head portion 524 and 525, respectively. Each pair of the generally parallel posts 522 and 523 define an archwire guide slot 526 of approximately 0.018 to 0.022 inch therebetween to slidingly engage an archwire.

As stated above, the shape memory brackets of the present invention are self-ligating. With regard to the single wing embodiments, at least one of the tie wing posts, or a portion thereof, is formed of a shape memory material. In the embodiment shown in FIGS. 20A-20C, both of the tie wing posts 522 and 523 of each pair of tie wing posts of the tie wing 520 are formed of a material which allows the tie wing 520 to flex to permit insertion or removal of the archwire relative to the guide slot 526.

In preferred embodiments, brackets of the present invention are formed of a shape memory metallic material, including metallic alloys, such as a nickel-titanium material, and/or of a shape memory non-metallic material, including resins and polymer materials, both along the base 512 and the tie wing 520. This material exhibits superelasticity and, therefore, shape memory, such that when the posts 522 and 523 of each pair of tie wing posts are flexed from a predetermined or rest position, the, head portions 524 and 525 of each tie wing posts separate to permit the insertion or removal of the archwire therebetween. Once force is removed, the posts 522 and 523 return to the original predetermined position.

To securely retain an archwire within the guide slot 526, the tie wing 520 includes inner opposing flanges 531 and 532, respectively. The inner flanges 531 and 532 are spaced at a distance “D” of approximately 0.010-0.014 inch which is smaller than the diameter of the archwire. In some embodiments, the flanges 531 and 532 may actually touch one another such that the distance “D” is zero. Further, the inner flanges 531 and 532 may be the same or different sizes.

Each head portion 524 and 525 of tie wing post 522 and 523, respectively, further includes an outer tie wing flange 534 and 535, respectively, which may be used in a conventional manner to secure archwires with ligature wires and other attachments during patient treatment, as necessary. In the preferred embodiments, the entire outer surface of each of the head portions 524 and 525 is shown as being generally convex, and the inner flanges 531 and 532, respectively, tapering downwardly and inwardly relative to one another.

As an alternative to the embodiment of the single wing bracket shown in FIGS. 20A and 20C, another embodiment to promote flexing of a tie wing is shown in FIG. 20B. A bracket 510′ includes a base 512′ and a tie wing 520′ having two pair of opposing tie wing posts 522′ and 523′ that each have an outer concave surface 39. Thus, the bracket 510′ is essentially the same as the bracket 510 but includes a single tie wing 520′ having two pairs of tie wing posts 522′ and 523′ with concave outer surfaces 39. The concave outer surface 39 of each of the tie wing posts 522′ and 523′ essentially provides areas of reduced thickness so as to provide additional flexing of the tie wing 520′.

As set forth above, the self-ligating brackets of the present invention can be twin brackets, single wing brackets, hybrid brackets, or any other type of bracket having any number of tie wings. The brackets of the invention can also include bracket bases and tie wings of any shape, thickness, material, or size, and the tie wings can be position in various locations and gingival offsets on the bracket bases. Further, the brackets of the present invention may be placed on various tooth surfaces, including the front surface and the rear surface of the tooth.

Due to the shape memory material from which the brackets of the present invention are formed, very low friction surfaces are presented for guidingly engaging the archwire. The lower friction between the bracket and the archwire, the more smoothly and easily the archwire will function to move a patient's tooth to a desired position, thus facilitating patient treatment. In this respect, the present invention also provides for further decreasing the frictional surface resistance of the brackets by allowing the brackets to be coated with other materials. By way of example, except the bonding base pad or mesh, the surface of the brackets including the tie wings and base, especially in the area of the guide slots, may be plated or electroplated with metallic elements such as nickel, gold, copper, silver, or the like. As opposed to a plating with metallic material, the brackets, except the bonding base pad or mesh may be coated with different plastics including polytetrafluoroethylene (PTFE) including Teflon™, thermosetting polymers or other polymers, with or without coupling agents which are specifically provided to create a smoother surface and thereby reduce friction.

In accordance with the invention, the surface treatments may also include coloring agents. It may be desired to increase the aesthetic appearance of new orthodontic brackets by including coloring agents which would present hues of gold, tooth color, red, green, blue or other colors.

To facilitate the coating process, the surface of the orthodontic bracket and the tie wings may be micro-etched, chemically etched, or mechanically pitted such as by blasting to create a surface roughness to facilitate bonding of a coating material.

The orthodontic brackets of the present invention are preferably used with archwires which are also formed of a nickel-titanium material, such as Nitinol™, which is a superelastic metallic material which exhibits flexibility and has a shape memory.

The flexibility of the nickel-titanium, or other material exhibiting shape memory, self-ligating brackets of the present invention and the small compact tie wing design of the invention make it easy for the brackets to be used in particularly difficult areas and small confines within a patient's mouth and may be used with or without the need for conventional elastic or metal ligatures to hold the archwire in place during patient treatment. Additionally, elastomeric colors, elastomeric ties, elastomeric power chains, directional elastics and/or various attachments may be added to the bracket to facilitate a smooth orthodontic treatment. The present invention promotes patient treatment by further facilitating an efficient mechanical movement between the archwire and the orthodontic brackets which will reduce patient treatment time and therefore increase patient comfort.

The foregoing description of the preferred embodiment of the invention has been presented to illustrate the principles of the invention and not to limit the invention to the particular embodiment illustrated. It is intended that the scope of the invention be defined by all of the embodiments encompassed within the following claims and their equivalents. 

1. A self-ligating orthodontic bracket comprising: a unitary body structure including a bracket base having front and rear surfaces and at least one tie wing, said at least one tie wing having a base portion extending from said front surface of said bracket base and at least one pair of opposing tie wing posts, said at least one pair of opposing tie wing posts defining an archwire guide slot therebetween of a first dimension to slidingly receive an archwire therein, each tie wing post of said at least one pair of opposing tie wing posts including a head portion, at least one head portion having an outwardly extending flange and at least one head portion having an inwardly extending flange, said inwardly extending flange being in a predetermined position relative to an opposing tie wing post to retain an archwire within said archwire guide slot, wherein at least a portion of the bracket being formed of a material such that at least one tie wing exhibits flexibility and shape memory effect allowing movement of said at least one tie wing to permit insertion or removal of an archwire relative to said archwire guide slot, afterwhich said at least one tie wing returns to the predetermined position.
 2. The self-ligating orthodontic bracket of claim 1, further comprising a pair of spaced opposing tie wings, each of said opposing tie wings exhibits flexibility and shape memory effect.
 3. The self-ligating orthodontic bracket of claim 1, wherein each head portion of said at least one pair of opposing tie wing posts includes an inwardly extending flange.
 4. The self-ligating orthodontic bracket of claim 1, wherein said bracket base and said at least one tie wing are formed of a material which exhibits shape memory effect.
 5. The self-ligating orthodontic brackets of claim 3, wherein said material is a nickel-titanium material.
 6. The self-ligating orthodontic brackets of claim 2, wherein said material is a nickel-titanium material.
 7. The self-ligating orthodontic bracket of claim 1, wherein said material is a nickel-titanium material.
 8. The self-ligating orthodontic bracket of claim 1, further comprising an area of reduced thickness adjacent to said base portion of at least one of said opposing tie wing posts of said at least one tie wing to facilitate flexing.
 9. The self-ligating orthodontic bracket of claim 1, wherein at least one of said opposing tie wing posts has an area of reduced thickness to promote flexing of said at least one tie wing.
 10. The self-ligating orthodontic bracket of claim 1, further comprising an alignment recess formed centrally in said front surface of said bracket base.
 11. The self-ligating orthodontic bracket of claim 1, further comprising a horizontal alignment recess formed centrally in said front surface of said bracket base.
 12. The self-ligating orthodontic bracket of claim 1, further comprising a vertical alignment recess formed centrally in said front surface of said bracket base.
 13. The self-ligating orthodontic bracket of claim 2, wherein said pair of spaced opposing tie wings are aligned with one another and spaced adjacent a gingival edge of said bracket base.
 14. The self-ligating orthodontic bracket of claim 13, further comprising an alignment recess formed centrally in said front surface of said bracket base.
 15. The self-ligating orthodontic bracket of claim 13 further comprising a horizontal alignment recess formed centrally in said front surface of said bracket base.
 16. The self-ligating orthodontic bracket of claim 1, wherein said bracket base and said at least one tie wing are coated with a coating material selected from a group of materials consisting of metallic materials, non-metallic materials, and polymers.
 17. The self-ligating orthodontic bracket of claim 16, wherein said non-metallic polymers are thermosetting polymers.
 18. The self-ligating orthodontic bracket of claim 16, wherein said coating material includes a coloring agent.
 19. The self-ligating orthodontic bracket of claim 1, wherein at least one archwire guide slot is coated with a coating material selected from a group of materials exhibiting a low coefficient of friction consisting of metallic materials and non-metallic polymers.
 20. The self-ligating orthodontic bracket of claim 19, wherein said non-metallic polymers are thermosetting polymers.
 21. The self-ligating orthodontic bracket of claim 19, in which said coating material includes a coloring agent.
 22. The self-ligating orthodontic bracket of claim 19, wherein the coating material is a material applied by electroplating.
 23. The self-ligating orthodontic bracket of claim 1, wherein said material is selected from a group of materials exhibiting shape memory consisting of metallic materials and non-metallic materials.
 24. The self-ligating orthodontic bracket of claim 1, further comprising an auxiliary attachment.
 25. The self-ligating orthodontic bracket of claim 24, wherein the auxiliary attachment is selected from the group consisting of Kobayashi hooks, removeable hook pins, hooks, uprighting springs, pins, metal ligatures, directional force elastics, elastomeric ligatures, and elastomeric power chains.
 26. The self-ligating orthodontic bracket of claim 2, further comprising an auxiliary attachment.
 27. The self-ligating orthodontic bracket of claim 26, wherein the auxiliary attachment is selected from the group consisting of Kobayashi hooks, hooks, removeable hook pins, uprighting springs, pins, metal ligatures, directional force elastics, elastomeric ligatures, and elastomeric power chains.
 28. The self-ligating orthodontic bracket of claim 1, further comprising at least one identification recess.
 29. The self-ligating orthodontic bracket of claim 28, wherein said at least one identification recess is color-coded.
 30. The self-ligating orthodontic bracket of claim 1, further comprising a platform located between said bracket base and said base portion of said at least one tie wing.
 31. The self-ligating orthodontic bracket of claim 30, wherein the platform includes a vertical slot therethrough.
 32. The self-ligating orthodontic bracket of claim 31, further comprising an area of reduced thickness adjacent to said base portion of at least one of said opposing tie wing posts of said at least one tie wing to facilitate flexing.
 33. The self-ligating orthodontic bracket of claim 2, further comprising a platform located between said bracket base and said base portion of said at least one tie wing, said platform including a vertical slot therethrough.
 34. The self-ligating orthodontic bracket of claim 33, further comprising an area of reduced thickness adjacent to said base portion of at least one of said opposing tie wing posts of said at least one tie wing to facilitate flexing.
 35. The self-ligating orthodontic bracket of claim 1, wherein the bracket is a Lewis-type bracket.
 36. The self-ligating orthodontic bracket of claim 35, further comprising an area of reduced thickness adjacent to said base portion of at least one of said opposing tie wing posts of said at least one tie wing to facilitate flexing.
 37. The self-ligating orthodontic bracket of claim 1, wherein the bracket is a Lang-type bracket.
 38. The self-ligating orthodontic bracket of claim 37, further comprising an area of reduced thickness adjacent to said base portion of at least one of said opposing tie wing posts of said at least one tie wing to facilitate flexing.
 39. The self-ligating orthodontic bracket of claim 1, wherein the bracket is a Creekmore-type bracket.
 40. The self-ligating orthodontic bracket of claim 39, further comprising an area of reduced thickness adjacent to said base portion of at least one of said opposing tie wing posts of said at least one tie wing to facilitate flexing.
 41. The self-ligating orthodontic bracket of claim 1, wherein the bracket is a hybrid bracket.
 42. The self-ligating orthodontic bracket of claim 41, further comprising an area of reduced thickness adjacent to said base portion of at least one of said opposing tie wing posts of said at least one tie wing to facilitate flexing.
 43. The self-ligating orthodontic bracket of claim 1, wherein the bracket is of a torque-in-base configuration.
 44. The self-ligating orthodontic bracket of claim 43, wherein the bracket is of a slot angulation configuration.
 45. The self-ligating orthodontic bracket of claim 1, wherein the bracket is of a torque-in-slot configuration.
 46. The self-ligating orthodontic bracket of claim 45, wherein the bracket is of a slot angulation configuration.
 47. The self-ligating orthodontic bracket of claim 2, wherein the bracket is a Lewis-type bracket.
 48. The self-ligating orthodontic bracket of claim 47, further comprising an area of reduced thickness adjacent to said base portion of at least one of said opposing tie wing posts of said at least one tie wing to facilitate flexing.
 49. The self-ligating orthodontic bracket of claim 2, wherein the bracket is a Lang-type bracket.
 50. The self-ligating orthodontic bracket of claim 49, further comprising an area of reduced thickness adjacent to said base portion of at least one of said opposing tie wing posts of said at least one tie wing to facilitate flexing.
 51. The self-ligating orthodontic bracket of claim 2, wherein the bracket is a Creekmore-type bracket.
 52. The self-ligating orthodontic bracket of claim 51, further comprising an area of reduced thickness adjacent to said base portion of at least one of said opposing tie wing posts of said at least one tie wing to facilitate flexing.
 53. The self-ligating orthodontic bracket of claim 2, wherein the bracket is of a torque-in-base configuration and of a slot angulation configuration.
 54. The self-ligating orthodontic bracket-of claim 2, wherein the bracket is of a torque-in-slot configuration and of a slot angulation configuration. 